1. Technology Field
The disclosure relates to an electronic device. Particularly, the disclosure relates to an electronic device having a complete power-saving mechanism.
2. Description of Related Art
An electronic device is generally equipped with a corresponding power device to provide power required by the system, for example, a power adapter used by a mobile phone and a notebook computer, or a power supplier used by a computer. Generally, the power device generates a voltage required by the system through an alternating current (AC)/direct current (DC) converter or a DC/DC converter. The AC/DC converter coverts an AC voltage into a DC voltage required by the system through a transformer and a rectifier voltage stabilizing circuit, which causes relatively large power consumption.
To effectively use energy, the existing power device generally provides two types of power including a main power and a standby power. When the electronic device is shut down, the power device continually provides the standby power, and a control unit in internal of the electronic device determines whether or not to perform a start-up procedure by detecting a pressed state of a power switch. Namely, when the electronic device is shut down or is waiting to start up, the power device itself has a certain amount of power consumption. For example, when a notebook computer is shut down and a battery thereof is in a fully charged state, and a power adapter thereof still has power consumption of 100-300 milliwatts. A general flat panel computer still has power consumption of 20 milliwatts in a shut down state.
In other words, when the existing electronic device is shut down or is waiting to start up, it still has a certain amount of power consumption, which causes waste of power and environment pollution. Moreover, although a power plug can be unplugged to avoid the power consumption of the electronic device in the shut down state, frequent plugging/unplugging of the power plug may not only cause damage of a power line or a plug wire, but can easily cause a risk of fire of the electric wire. Moreover, regarding some tablet computers, power of theses devices cannot be removed, and after being manufactured, a battery thereof is probably charged to at least a half of a total power, so that in case that the power cannot be removed, the whole tablet computer continually consumes power of about 20 milliwatts. Therefore, when the user purchases a tablet computer which has been manufactured for two or three months, the user has to recharge the tablet computer and can not promptly use the tablet computer.